xref: /linux/sound/soc/stm/stm32_i2s.c (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  STM32 ALSA SoC Digital Audio Interface (I2S) driver.
4  *
5  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
6  * Author(s): Olivier Moysan <olivier.moysan@st.com> for STMicroelectronics.
7  */
8 
9 #include <linux/bitfield.h>
10 #include <linux/clk.h>
11 #include <linux/clk-provider.h>
12 #include <linux/delay.h>
13 #include <linux/module.h>
14 #include <linux/of_irq.h>
15 #include <linux/of_platform.h>
16 #include <linux/regmap.h>
17 #include <linux/reset.h>
18 #include <linux/spinlock.h>
19 
20 #include <sound/dmaengine_pcm.h>
21 #include <sound/pcm_params.h>
22 
23 #define STM32_I2S_CR1_REG	0x0
24 #define STM32_I2S_CFG1_REG	0x08
25 #define STM32_I2S_CFG2_REG	0x0C
26 #define STM32_I2S_IER_REG	0x10
27 #define STM32_I2S_SR_REG	0x14
28 #define STM32_I2S_IFCR_REG	0x18
29 #define STM32_I2S_TXDR_REG	0X20
30 #define STM32_I2S_RXDR_REG	0x30
31 #define STM32_I2S_CGFR_REG	0X50
32 #define STM32_I2S_HWCFGR_REG	0x3F0
33 #define STM32_I2S_VERR_REG	0x3F4
34 #define STM32_I2S_IPIDR_REG	0x3F8
35 #define STM32_I2S_SIDR_REG	0x3FC
36 
37 /* Bit definition for SPI2S_CR1 register */
38 #define I2S_CR1_SPE		BIT(0)
39 #define I2S_CR1_CSTART		BIT(9)
40 #define I2S_CR1_CSUSP		BIT(10)
41 #define I2S_CR1_HDDIR		BIT(11)
42 #define I2S_CR1_SSI		BIT(12)
43 #define I2S_CR1_CRC33_17	BIT(13)
44 #define I2S_CR1_RCRCI		BIT(14)
45 #define I2S_CR1_TCRCI		BIT(15)
46 
47 /* Bit definition for SPI_CFG2 register */
48 #define I2S_CFG2_IOSWP_SHIFT	15
49 #define I2S_CFG2_IOSWP		BIT(I2S_CFG2_IOSWP_SHIFT)
50 #define I2S_CFG2_LSBFRST	BIT(23)
51 #define I2S_CFG2_AFCNTR		BIT(31)
52 
53 /* Bit definition for SPI_CFG1 register */
54 #define I2S_CFG1_FTHVL_SHIFT	5
55 #define I2S_CFG1_FTHVL_MASK	GENMASK(8, I2S_CFG1_FTHVL_SHIFT)
56 #define I2S_CFG1_FTHVL_SET(x)	((x) << I2S_CFG1_FTHVL_SHIFT)
57 
58 #define I2S_CFG1_TXDMAEN	BIT(15)
59 #define I2S_CFG1_RXDMAEN	BIT(14)
60 
61 /* Bit definition for SPI2S_IER register */
62 #define I2S_IER_RXPIE		BIT(0)
63 #define I2S_IER_TXPIE		BIT(1)
64 #define I2S_IER_DPXPIE		BIT(2)
65 #define I2S_IER_EOTIE		BIT(3)
66 #define I2S_IER_TXTFIE		BIT(4)
67 #define I2S_IER_UDRIE		BIT(5)
68 #define I2S_IER_OVRIE		BIT(6)
69 #define I2S_IER_CRCEIE		BIT(7)
70 #define I2S_IER_TIFREIE		BIT(8)
71 #define I2S_IER_MODFIE		BIT(9)
72 #define I2S_IER_TSERFIE		BIT(10)
73 
74 /* Bit definition for SPI2S_SR register */
75 #define I2S_SR_RXP		BIT(0)
76 #define I2S_SR_TXP		BIT(1)
77 #define I2S_SR_DPXP		BIT(2)
78 #define I2S_SR_EOT		BIT(3)
79 #define I2S_SR_TXTF		BIT(4)
80 #define I2S_SR_UDR		BIT(5)
81 #define I2S_SR_OVR		BIT(6)
82 #define I2S_SR_CRCERR		BIT(7)
83 #define I2S_SR_TIFRE		BIT(8)
84 #define I2S_SR_MODF		BIT(9)
85 #define I2S_SR_TSERF		BIT(10)
86 #define I2S_SR_SUSP		BIT(11)
87 #define I2S_SR_TXC		BIT(12)
88 #define I2S_SR_RXPLVL		GENMASK(14, 13)
89 #define I2S_SR_RXWNE		BIT(15)
90 
91 #define I2S_SR_MASK		GENMASK(15, 0)
92 
93 /* Bit definition for SPI_IFCR register */
94 #define I2S_IFCR_EOTC		BIT(3)
95 #define I2S_IFCR_TXTFC		BIT(4)
96 #define I2S_IFCR_UDRC		BIT(5)
97 #define I2S_IFCR_OVRC		BIT(6)
98 #define I2S_IFCR_CRCEC		BIT(7)
99 #define I2S_IFCR_TIFREC		BIT(8)
100 #define I2S_IFCR_MODFC		BIT(9)
101 #define I2S_IFCR_TSERFC		BIT(10)
102 #define I2S_IFCR_SUSPC		BIT(11)
103 
104 #define I2S_IFCR_MASK		GENMASK(11, 3)
105 
106 /* Bit definition for SPI_I2SCGFR register */
107 #define I2S_CGFR_I2SMOD		BIT(0)
108 
109 #define I2S_CGFR_I2SCFG_SHIFT	1
110 #define I2S_CGFR_I2SCFG_MASK	GENMASK(3, I2S_CGFR_I2SCFG_SHIFT)
111 #define I2S_CGFR_I2SCFG_SET(x)	((x) << I2S_CGFR_I2SCFG_SHIFT)
112 
113 #define I2S_CGFR_I2SSTD_SHIFT	4
114 #define I2S_CGFR_I2SSTD_MASK	GENMASK(5, I2S_CGFR_I2SSTD_SHIFT)
115 #define I2S_CGFR_I2SSTD_SET(x)	((x) << I2S_CGFR_I2SSTD_SHIFT)
116 
117 #define I2S_CGFR_PCMSYNC	BIT(7)
118 
119 #define I2S_CGFR_DATLEN_SHIFT	8
120 #define I2S_CGFR_DATLEN_MASK	GENMASK(9, I2S_CGFR_DATLEN_SHIFT)
121 #define I2S_CGFR_DATLEN_SET(x)	((x) << I2S_CGFR_DATLEN_SHIFT)
122 
123 #define I2S_CGFR_CHLEN_SHIFT	10
124 #define I2S_CGFR_CHLEN		BIT(I2S_CGFR_CHLEN_SHIFT)
125 #define I2S_CGFR_CKPOL		BIT(11)
126 #define I2S_CGFR_FIXCH		BIT(12)
127 #define I2S_CGFR_WSINV		BIT(13)
128 #define I2S_CGFR_DATFMT		BIT(14)
129 
130 #define I2S_CGFR_I2SDIV_SHIFT	16
131 #define I2S_CGFR_I2SDIV_BIT_H	23
132 #define I2S_CGFR_I2SDIV_MASK	GENMASK(I2S_CGFR_I2SDIV_BIT_H,\
133 				I2S_CGFR_I2SDIV_SHIFT)
134 #define I2S_CGFR_I2SDIV_SET(x)	((x) << I2S_CGFR_I2SDIV_SHIFT)
135 #define	I2S_CGFR_I2SDIV_MAX	((1 << (I2S_CGFR_I2SDIV_BIT_H -\
136 				I2S_CGFR_I2SDIV_SHIFT)) - 1)
137 
138 #define I2S_CGFR_ODD_SHIFT	24
139 #define I2S_CGFR_ODD		BIT(I2S_CGFR_ODD_SHIFT)
140 #define I2S_CGFR_MCKOE		BIT(25)
141 
142 /* Registers below apply to I2S version 1.1 and more */
143 
144 /* Bit definition for SPI_HWCFGR register */
145 #define I2S_HWCFGR_I2S_SUPPORT_MASK	GENMASK(15, 12)
146 
147 /* Bit definition for SPI_VERR register */
148 #define I2S_VERR_MIN_MASK	GENMASK(3, 0)
149 #define I2S_VERR_MAJ_MASK	GENMASK(7, 4)
150 
151 /* Bit definition for SPI_IPIDR register */
152 #define I2S_IPIDR_ID_MASK	GENMASK(31, 0)
153 
154 /* Bit definition for SPI_SIDR register */
155 #define I2S_SIDR_ID_MASK	GENMASK(31, 0)
156 
157 #define I2S_IPIDR_NUMBER	0x00130022
158 
159 enum i2s_master_mode {
160 	I2S_MS_NOT_SET,
161 	I2S_MS_MASTER,
162 	I2S_MS_SLAVE,
163 };
164 
165 enum i2s_mode {
166 	I2S_I2SMOD_TX_SLAVE,
167 	I2S_I2SMOD_RX_SLAVE,
168 	I2S_I2SMOD_TX_MASTER,
169 	I2S_I2SMOD_RX_MASTER,
170 	I2S_I2SMOD_FD_SLAVE,
171 	I2S_I2SMOD_FD_MASTER,
172 };
173 
174 enum i2s_fifo_th {
175 	I2S_FIFO_TH_NONE,
176 	I2S_FIFO_TH_ONE_QUARTER,
177 	I2S_FIFO_TH_HALF,
178 	I2S_FIFO_TH_THREE_QUARTER,
179 	I2S_FIFO_TH_FULL,
180 };
181 
182 enum i2s_std {
183 	I2S_STD_I2S,
184 	I2S_STD_LEFT_J,
185 	I2S_STD_RIGHT_J,
186 	I2S_STD_DSP,
187 };
188 
189 enum i2s_datlen {
190 	I2S_I2SMOD_DATLEN_16,
191 	I2S_I2SMOD_DATLEN_24,
192 	I2S_I2SMOD_DATLEN_32,
193 };
194 
195 #define STM32_I2S_FIFO_SIZE		16
196 
197 #define STM32_I2S_IS_MASTER(x)		((x)->ms_flg == I2S_MS_MASTER)
198 #define STM32_I2S_IS_SLAVE(x)		((x)->ms_flg == I2S_MS_SLAVE)
199 
200 #define STM32_I2S_NAME_LEN		32
201 #define STM32_I2S_RATE_11K		11025
202 
203 /**
204  * struct stm32_i2s_data - private data of I2S
205  * @regmap_conf: I2S register map configuration pointer
206  * @regmap: I2S register map pointer
207  * @pdev: device data pointer
208  * @dai_drv: DAI driver pointer
209  * @dma_data_tx: dma configuration data for tx channel
210  * @dma_data_rx: dma configuration data for tx channel
211  * @substream: PCM substream data pointer
212  * @i2sclk: kernel clock feeding the I2S clock generator
213  * @i2smclk: master clock from I2S mclk provider
214  * @pclk: peripheral clock driving bus interface
215  * @x8kclk: I2S parent clock for sampling frequencies multiple of 8kHz
216  * @x11kclk: I2S parent clock for sampling frequencies multiple of 11kHz
217  * @base:  mmio register base virtual address
218  * @phys_addr: I2S registers physical base address
219  * @lock_fd: lock to manage race conditions in full duplex mode
220  * @irq_lock: prevent race condition with IRQ
221  * @mclk_rate: master clock frequency (Hz)
222  * @fmt: DAI protocol
223  * @divider: prescaler division ratio
224  * @div: prescaler div field
225  * @odd: prescaler odd field
226  * @refcount: keep count of opened streams on I2S
227  * @ms_flg: master mode flag.
228  */
229 struct stm32_i2s_data {
230 	const struct regmap_config *regmap_conf;
231 	struct regmap *regmap;
232 	struct platform_device *pdev;
233 	struct snd_soc_dai_driver *dai_drv;
234 	struct snd_dmaengine_dai_dma_data dma_data_tx;
235 	struct snd_dmaengine_dai_dma_data dma_data_rx;
236 	struct snd_pcm_substream *substream;
237 	struct clk *i2sclk;
238 	struct clk *i2smclk;
239 	struct clk *pclk;
240 	struct clk *x8kclk;
241 	struct clk *x11kclk;
242 	void __iomem *base;
243 	dma_addr_t phys_addr;
244 	spinlock_t lock_fd; /* Manage race conditions for full duplex */
245 	spinlock_t irq_lock; /* used to prevent race condition with IRQ */
246 	unsigned int mclk_rate;
247 	unsigned int fmt;
248 	unsigned int divider;
249 	unsigned int div;
250 	bool odd;
251 	int refcount;
252 	int ms_flg;
253 };
254 
255 struct stm32_i2smclk_data {
256 	struct clk_hw hw;
257 	unsigned long freq;
258 	struct stm32_i2s_data *i2s_data;
259 };
260 
261 #define to_mclk_data(_hw) container_of(_hw, struct stm32_i2smclk_data, hw)
262 
263 static int stm32_i2s_calc_clk_div(struct stm32_i2s_data *i2s,
264 				  unsigned long input_rate,
265 				  unsigned long output_rate)
266 {
267 	unsigned int ratio, div, divider = 1;
268 	bool odd;
269 
270 	ratio = DIV_ROUND_CLOSEST(input_rate, output_rate);
271 
272 	/* Check the parity of the divider */
273 	odd = ratio & 0x1;
274 
275 	/* Compute the div prescaler */
276 	div = ratio >> 1;
277 
278 	/* If div is 0 actual divider is 1 */
279 	if (div) {
280 		divider = ((2 * div) + odd);
281 		dev_dbg(&i2s->pdev->dev, "Divider: 2*%d(div)+%d(odd) = %d\n",
282 			div, odd, divider);
283 	}
284 
285 	/* Division by three is not allowed by I2S prescaler */
286 	if ((div == 1 && odd) || div > I2S_CGFR_I2SDIV_MAX) {
287 		dev_err(&i2s->pdev->dev, "Wrong divider setting\n");
288 		return -EINVAL;
289 	}
290 
291 	if (input_rate % divider)
292 		dev_dbg(&i2s->pdev->dev,
293 			"Rate not accurate. requested (%ld), actual (%ld)\n",
294 			output_rate, input_rate / divider);
295 
296 	i2s->div = div;
297 	i2s->odd = odd;
298 	i2s->divider = divider;
299 
300 	return 0;
301 }
302 
303 static int stm32_i2s_set_clk_div(struct stm32_i2s_data *i2s)
304 {
305 	u32 cgfr, cgfr_mask;
306 
307 	cgfr = I2S_CGFR_I2SDIV_SET(i2s->div) | (i2s->odd << I2S_CGFR_ODD_SHIFT);
308 	cgfr_mask = I2S_CGFR_I2SDIV_MASK | I2S_CGFR_ODD;
309 
310 	return regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG,
311 				  cgfr_mask, cgfr);
312 }
313 
314 static int stm32_i2s_set_parent_clock(struct stm32_i2s_data *i2s,
315 				      unsigned int rate)
316 {
317 	struct platform_device *pdev = i2s->pdev;
318 	struct clk *parent_clk;
319 	int ret;
320 
321 	if (!(rate % STM32_I2S_RATE_11K))
322 		parent_clk = i2s->x11kclk;
323 	else
324 		parent_clk = i2s->x8kclk;
325 
326 	ret = clk_set_parent(i2s->i2sclk, parent_clk);
327 	if (ret)
328 		dev_err(&pdev->dev,
329 			"Error %d setting i2sclk parent clock\n", ret);
330 
331 	return ret;
332 }
333 
334 static long stm32_i2smclk_round_rate(struct clk_hw *hw, unsigned long rate,
335 				     unsigned long *prate)
336 {
337 	struct stm32_i2smclk_data *mclk = to_mclk_data(hw);
338 	struct stm32_i2s_data *i2s = mclk->i2s_data;
339 	int ret;
340 
341 	ret = stm32_i2s_calc_clk_div(i2s, *prate, rate);
342 	if (ret)
343 		return ret;
344 
345 	mclk->freq = *prate / i2s->divider;
346 
347 	return mclk->freq;
348 }
349 
350 static unsigned long stm32_i2smclk_recalc_rate(struct clk_hw *hw,
351 					       unsigned long parent_rate)
352 {
353 	struct stm32_i2smclk_data *mclk = to_mclk_data(hw);
354 
355 	return mclk->freq;
356 }
357 
358 static int stm32_i2smclk_set_rate(struct clk_hw *hw, unsigned long rate,
359 				  unsigned long parent_rate)
360 {
361 	struct stm32_i2smclk_data *mclk = to_mclk_data(hw);
362 	struct stm32_i2s_data *i2s = mclk->i2s_data;
363 	int ret;
364 
365 	ret = stm32_i2s_calc_clk_div(i2s, parent_rate, rate);
366 	if (ret)
367 		return ret;
368 
369 	ret = stm32_i2s_set_clk_div(i2s);
370 	if (ret)
371 		return ret;
372 
373 	mclk->freq = rate;
374 
375 	return 0;
376 }
377 
378 static int stm32_i2smclk_enable(struct clk_hw *hw)
379 {
380 	struct stm32_i2smclk_data *mclk = to_mclk_data(hw);
381 	struct stm32_i2s_data *i2s = mclk->i2s_data;
382 
383 	dev_dbg(&i2s->pdev->dev, "Enable master clock\n");
384 
385 	return regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG,
386 				    I2S_CGFR_MCKOE, I2S_CGFR_MCKOE);
387 }
388 
389 static void stm32_i2smclk_disable(struct clk_hw *hw)
390 {
391 	struct stm32_i2smclk_data *mclk = to_mclk_data(hw);
392 	struct stm32_i2s_data *i2s = mclk->i2s_data;
393 
394 	dev_dbg(&i2s->pdev->dev, "Disable master clock\n");
395 
396 	regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG, I2S_CGFR_MCKOE, 0);
397 }
398 
399 static const struct clk_ops mclk_ops = {
400 	.enable = stm32_i2smclk_enable,
401 	.disable = stm32_i2smclk_disable,
402 	.recalc_rate = stm32_i2smclk_recalc_rate,
403 	.round_rate = stm32_i2smclk_round_rate,
404 	.set_rate = stm32_i2smclk_set_rate,
405 };
406 
407 static int stm32_i2s_add_mclk_provider(struct stm32_i2s_data *i2s)
408 {
409 	struct clk_hw *hw;
410 	struct stm32_i2smclk_data *mclk;
411 	struct device *dev = &i2s->pdev->dev;
412 	const char *pname = __clk_get_name(i2s->i2sclk);
413 	char *mclk_name, *p, *s = (char *)pname;
414 	int ret, i = 0;
415 
416 	mclk = devm_kzalloc(dev, sizeof(*mclk), GFP_KERNEL);
417 	if (!mclk)
418 		return -ENOMEM;
419 
420 	mclk_name = devm_kcalloc(dev, sizeof(char),
421 				 STM32_I2S_NAME_LEN, GFP_KERNEL);
422 	if (!mclk_name)
423 		return -ENOMEM;
424 
425 	/*
426 	 * Forge mclk clock name from parent clock name and suffix.
427 	 * String after "_" char is stripped in parent name.
428 	 */
429 	p = mclk_name;
430 	while (*s && *s != '_' && (i < (STM32_I2S_NAME_LEN - 7))) {
431 		*p++ = *s++;
432 		i++;
433 	}
434 	strcat(p, "_mclk");
435 
436 	mclk->hw.init = CLK_HW_INIT(mclk_name, pname, &mclk_ops, 0);
437 	mclk->i2s_data = i2s;
438 	hw = &mclk->hw;
439 
440 	dev_dbg(dev, "Register master clock %s\n", mclk_name);
441 	ret = devm_clk_hw_register(&i2s->pdev->dev, hw);
442 	if (ret) {
443 		dev_err(dev, "mclk register fails with error %d\n", ret);
444 		return ret;
445 	}
446 	i2s->i2smclk = hw->clk;
447 
448 	/* register mclk provider */
449 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw);
450 }
451 
452 static irqreturn_t stm32_i2s_isr(int irq, void *devid)
453 {
454 	struct stm32_i2s_data *i2s = (struct stm32_i2s_data *)devid;
455 	struct platform_device *pdev = i2s->pdev;
456 	u32 sr, ier;
457 	unsigned long flags;
458 	int err = 0;
459 
460 	regmap_read(i2s->regmap, STM32_I2S_SR_REG, &sr);
461 	regmap_read(i2s->regmap, STM32_I2S_IER_REG, &ier);
462 
463 	flags = sr & ier;
464 	if (!flags) {
465 		dev_dbg(&pdev->dev, "Spurious IRQ sr=0x%08x, ier=0x%08x\n",
466 			sr, ier);
467 		return IRQ_NONE;
468 	}
469 
470 	regmap_write_bits(i2s->regmap, STM32_I2S_IFCR_REG,
471 			  I2S_IFCR_MASK, flags);
472 
473 	if (flags & I2S_SR_OVR) {
474 		dev_dbg(&pdev->dev, "Overrun\n");
475 		err = 1;
476 	}
477 
478 	if (flags & I2S_SR_UDR) {
479 		dev_dbg(&pdev->dev, "Underrun\n");
480 		err = 1;
481 	}
482 
483 	if (flags & I2S_SR_TIFRE)
484 		dev_dbg(&pdev->dev, "Frame error\n");
485 
486 	spin_lock(&i2s->irq_lock);
487 	if (err && i2s->substream)
488 		snd_pcm_stop_xrun(i2s->substream);
489 	spin_unlock(&i2s->irq_lock);
490 
491 	return IRQ_HANDLED;
492 }
493 
494 static bool stm32_i2s_readable_reg(struct device *dev, unsigned int reg)
495 {
496 	switch (reg) {
497 	case STM32_I2S_CR1_REG:
498 	case STM32_I2S_CFG1_REG:
499 	case STM32_I2S_CFG2_REG:
500 	case STM32_I2S_IER_REG:
501 	case STM32_I2S_SR_REG:
502 	case STM32_I2S_RXDR_REG:
503 	case STM32_I2S_CGFR_REG:
504 	case STM32_I2S_HWCFGR_REG:
505 	case STM32_I2S_VERR_REG:
506 	case STM32_I2S_IPIDR_REG:
507 	case STM32_I2S_SIDR_REG:
508 		return true;
509 	default:
510 		return false;
511 	}
512 }
513 
514 static bool stm32_i2s_volatile_reg(struct device *dev, unsigned int reg)
515 {
516 	switch (reg) {
517 	case STM32_I2S_SR_REG:
518 	case STM32_I2S_RXDR_REG:
519 		return true;
520 	default:
521 		return false;
522 	}
523 }
524 
525 static bool stm32_i2s_writeable_reg(struct device *dev, unsigned int reg)
526 {
527 	switch (reg) {
528 	case STM32_I2S_CR1_REG:
529 	case STM32_I2S_CFG1_REG:
530 	case STM32_I2S_CFG2_REG:
531 	case STM32_I2S_IER_REG:
532 	case STM32_I2S_IFCR_REG:
533 	case STM32_I2S_TXDR_REG:
534 	case STM32_I2S_CGFR_REG:
535 		return true;
536 	default:
537 		return false;
538 	}
539 }
540 
541 static int stm32_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
542 {
543 	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);
544 	u32 cgfr;
545 	u32 cgfr_mask =  I2S_CGFR_I2SSTD_MASK | I2S_CGFR_CKPOL |
546 			 I2S_CGFR_WSINV | I2S_CGFR_I2SCFG_MASK;
547 
548 	dev_dbg(cpu_dai->dev, "fmt %x\n", fmt);
549 
550 	/*
551 	 * winv = 0 : default behavior (high/low) for all standards
552 	 * ckpol = 0 for all standards.
553 	 */
554 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
555 	case SND_SOC_DAIFMT_I2S:
556 		cgfr = I2S_CGFR_I2SSTD_SET(I2S_STD_I2S);
557 		break;
558 	case SND_SOC_DAIFMT_MSB:
559 		cgfr = I2S_CGFR_I2SSTD_SET(I2S_STD_LEFT_J);
560 		break;
561 	case SND_SOC_DAIFMT_LSB:
562 		cgfr = I2S_CGFR_I2SSTD_SET(I2S_STD_RIGHT_J);
563 		break;
564 	case SND_SOC_DAIFMT_DSP_A:
565 		cgfr = I2S_CGFR_I2SSTD_SET(I2S_STD_DSP);
566 		break;
567 	/* DSP_B not mapped on I2S PCM long format. 1 bit offset does not fit */
568 	default:
569 		dev_err(cpu_dai->dev, "Unsupported protocol %#x\n",
570 			fmt & SND_SOC_DAIFMT_FORMAT_MASK);
571 		return -EINVAL;
572 	}
573 
574 	/* DAI clock strobing */
575 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
576 	case SND_SOC_DAIFMT_NB_NF:
577 		break;
578 	case SND_SOC_DAIFMT_IB_NF:
579 		cgfr |= I2S_CGFR_CKPOL;
580 		break;
581 	case SND_SOC_DAIFMT_NB_IF:
582 		cgfr |= I2S_CGFR_WSINV;
583 		break;
584 	case SND_SOC_DAIFMT_IB_IF:
585 		cgfr |= I2S_CGFR_CKPOL;
586 		cgfr |= I2S_CGFR_WSINV;
587 		break;
588 	default:
589 		dev_err(cpu_dai->dev, "Unsupported strobing %#x\n",
590 			fmt & SND_SOC_DAIFMT_INV_MASK);
591 		return -EINVAL;
592 	}
593 
594 	/* DAI clock master masks */
595 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
596 	case SND_SOC_DAIFMT_CBM_CFM:
597 		i2s->ms_flg = I2S_MS_SLAVE;
598 		break;
599 	case SND_SOC_DAIFMT_CBS_CFS:
600 		i2s->ms_flg = I2S_MS_MASTER;
601 		break;
602 	default:
603 		dev_err(cpu_dai->dev, "Unsupported mode %#x\n",
604 			fmt & SND_SOC_DAIFMT_MASTER_MASK);
605 		return -EINVAL;
606 	}
607 
608 	i2s->fmt = fmt;
609 	return regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG,
610 				  cgfr_mask, cgfr);
611 }
612 
613 static int stm32_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
614 				int clk_id, unsigned int freq, int dir)
615 {
616 	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);
617 	int ret = 0;
618 
619 	dev_dbg(cpu_dai->dev, "I2S MCLK frequency is %uHz. mode: %s, dir: %s\n",
620 		freq, STM32_I2S_IS_MASTER(i2s) ? "master" : "slave",
621 		dir ? "output" : "input");
622 
623 	/* MCLK generation is available only in master mode */
624 	if (dir == SND_SOC_CLOCK_OUT && STM32_I2S_IS_MASTER(i2s)) {
625 		if (!i2s->i2smclk) {
626 			dev_dbg(cpu_dai->dev, "No MCLK registered\n");
627 			return 0;
628 		}
629 
630 		/* Assume shutdown if requested frequency is 0Hz */
631 		if (!freq) {
632 			/* Release mclk rate only if rate was actually set */
633 			if (i2s->mclk_rate) {
634 				clk_rate_exclusive_put(i2s->i2smclk);
635 				i2s->mclk_rate = 0;
636 			}
637 			return regmap_update_bits(i2s->regmap,
638 						  STM32_I2S_CGFR_REG,
639 						  I2S_CGFR_MCKOE, 0);
640 		}
641 		/* If master clock is used, set parent clock now */
642 		ret = stm32_i2s_set_parent_clock(i2s, freq);
643 		if (ret)
644 			return ret;
645 		ret = clk_set_rate_exclusive(i2s->i2smclk, freq);
646 		if (ret) {
647 			dev_err(cpu_dai->dev, "Could not set mclk rate\n");
648 			return ret;
649 		}
650 		ret = regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG,
651 					 I2S_CGFR_MCKOE, I2S_CGFR_MCKOE);
652 		if (!ret)
653 			i2s->mclk_rate = freq;
654 	}
655 
656 	return ret;
657 }
658 
659 static int stm32_i2s_configure_clock(struct snd_soc_dai *cpu_dai,
660 				     struct snd_pcm_hw_params *params)
661 {
662 	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);
663 	unsigned long i2s_clock_rate;
664 	unsigned int nb_bits, frame_len;
665 	unsigned int rate = params_rate(params);
666 	u32 cgfr;
667 	int ret;
668 
669 	if (!(rate % 11025))
670 		clk_set_parent(i2s->i2sclk, i2s->x11kclk);
671 	else
672 		clk_set_parent(i2s->i2sclk, i2s->x8kclk);
673 	i2s_clock_rate = clk_get_rate(i2s->i2sclk);
674 
675 	/*
676 	 * mckl = mclk_ratio x ws
677 	 *   i2s mode : mclk_ratio = 256
678 	 *   dsp mode : mclk_ratio = 128
679 	 *
680 	 * mclk on
681 	 *   i2s mode : div = i2s_clk / (mclk_ratio * ws)
682 	 *   dsp mode : div = i2s_clk / (mclk_ratio * ws)
683 	 * mclk off
684 	 *   i2s mode : div = i2s_clk / (nb_bits x ws)
685 	 *   dsp mode : div = i2s_clk / (nb_bits x ws)
686 	 */
687 	if (i2s->mclk_rate) {
688 		ret = stm32_i2s_calc_clk_div(i2s, i2s_clock_rate,
689 					     i2s->mclk_rate);
690 		if (ret)
691 			return ret;
692 	} else {
693 		frame_len = 32;
694 		if ((i2s->fmt & SND_SOC_DAIFMT_FORMAT_MASK) ==
695 		    SND_SOC_DAIFMT_DSP_A)
696 			frame_len = 16;
697 
698 		/* master clock not enabled */
699 		ret = regmap_read(i2s->regmap, STM32_I2S_CGFR_REG, &cgfr);
700 		if (ret < 0)
701 			return ret;
702 
703 		nb_bits = frame_len * ((cgfr & I2S_CGFR_CHLEN) + 1);
704 		ret = stm32_i2s_calc_clk_div(i2s, i2s_clock_rate,
705 					     (nb_bits * rate));
706 		if (ret)
707 			return ret;
708 	}
709 
710 	ret = stm32_i2s_set_clk_div(i2s);
711 	if (ret < 0)
712 		return ret;
713 
714 	/* Set bitclock and frameclock to their inactive state */
715 	return regmap_update_bits(i2s->regmap, STM32_I2S_CFG2_REG,
716 				  I2S_CFG2_AFCNTR, I2S_CFG2_AFCNTR);
717 }
718 
719 static int stm32_i2s_configure(struct snd_soc_dai *cpu_dai,
720 			       struct snd_pcm_hw_params *params,
721 			       struct snd_pcm_substream *substream)
722 {
723 	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);
724 	int format = params_width(params);
725 	u32 cfgr, cfgr_mask, cfg1;
726 	unsigned int fthlv;
727 	int ret;
728 
729 	switch (format) {
730 	case 16:
731 		cfgr = I2S_CGFR_DATLEN_SET(I2S_I2SMOD_DATLEN_16);
732 		cfgr_mask = I2S_CGFR_DATLEN_MASK | I2S_CGFR_CHLEN;
733 		break;
734 	case 32:
735 		cfgr = I2S_CGFR_DATLEN_SET(I2S_I2SMOD_DATLEN_32) |
736 					   I2S_CGFR_CHLEN;
737 		cfgr_mask = I2S_CGFR_DATLEN_MASK | I2S_CGFR_CHLEN;
738 		break;
739 	default:
740 		dev_err(cpu_dai->dev, "Unexpected format %d", format);
741 		return -EINVAL;
742 	}
743 
744 	if (STM32_I2S_IS_SLAVE(i2s)) {
745 		cfgr |= I2S_CGFR_I2SCFG_SET(I2S_I2SMOD_FD_SLAVE);
746 
747 		/* As data length is either 16 or 32 bits, fixch always set */
748 		cfgr |= I2S_CGFR_FIXCH;
749 		cfgr_mask |= I2S_CGFR_FIXCH;
750 	} else {
751 		cfgr |= I2S_CGFR_I2SCFG_SET(I2S_I2SMOD_FD_MASTER);
752 	}
753 	cfgr_mask |= I2S_CGFR_I2SCFG_MASK;
754 
755 	ret = regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG,
756 				 cfgr_mask, cfgr);
757 	if (ret < 0)
758 		return ret;
759 
760 	fthlv = STM32_I2S_FIFO_SIZE * I2S_FIFO_TH_ONE_QUARTER / 4;
761 	cfg1 = I2S_CFG1_FTHVL_SET(fthlv - 1);
762 
763 	return regmap_update_bits(i2s->regmap, STM32_I2S_CFG1_REG,
764 				  I2S_CFG1_FTHVL_MASK, cfg1);
765 }
766 
767 static int stm32_i2s_startup(struct snd_pcm_substream *substream,
768 			     struct snd_soc_dai *cpu_dai)
769 {
770 	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);
771 	unsigned long flags;
772 	int ret;
773 
774 	spin_lock_irqsave(&i2s->irq_lock, flags);
775 	i2s->substream = substream;
776 	spin_unlock_irqrestore(&i2s->irq_lock, flags);
777 
778 	if ((i2s->fmt & SND_SOC_DAIFMT_FORMAT_MASK) != SND_SOC_DAIFMT_DSP_A)
779 		snd_pcm_hw_constraint_single(substream->runtime,
780 					     SNDRV_PCM_HW_PARAM_CHANNELS, 2);
781 
782 	ret = clk_prepare_enable(i2s->i2sclk);
783 	if (ret < 0) {
784 		dev_err(cpu_dai->dev, "Failed to enable clock: %d\n", ret);
785 		return ret;
786 	}
787 
788 	return regmap_write_bits(i2s->regmap, STM32_I2S_IFCR_REG,
789 				 I2S_IFCR_MASK, I2S_IFCR_MASK);
790 }
791 
792 static int stm32_i2s_hw_params(struct snd_pcm_substream *substream,
793 			       struct snd_pcm_hw_params *params,
794 			       struct snd_soc_dai *cpu_dai)
795 {
796 	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);
797 	int ret;
798 
799 	ret = stm32_i2s_configure(cpu_dai, params, substream);
800 	if (ret < 0) {
801 		dev_err(cpu_dai->dev, "Configuration returned error %d\n", ret);
802 		return ret;
803 	}
804 
805 	if (STM32_I2S_IS_MASTER(i2s))
806 		ret = stm32_i2s_configure_clock(cpu_dai, params);
807 
808 	return ret;
809 }
810 
811 static int stm32_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
812 			     struct snd_soc_dai *cpu_dai)
813 {
814 	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);
815 	bool playback_flg = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
816 	u32 cfg1_mask, ier;
817 	int ret;
818 
819 	switch (cmd) {
820 	case SNDRV_PCM_TRIGGER_START:
821 	case SNDRV_PCM_TRIGGER_RESUME:
822 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
823 		/* Enable i2s */
824 		dev_dbg(cpu_dai->dev, "start I2S %s\n",
825 			playback_flg ? "playback" : "capture");
826 
827 		cfg1_mask = I2S_CFG1_RXDMAEN | I2S_CFG1_TXDMAEN;
828 		regmap_update_bits(i2s->regmap, STM32_I2S_CFG1_REG,
829 				   cfg1_mask, cfg1_mask);
830 
831 		ret = regmap_update_bits(i2s->regmap, STM32_I2S_CR1_REG,
832 					 I2S_CR1_SPE, I2S_CR1_SPE);
833 		if (ret < 0) {
834 			dev_err(cpu_dai->dev, "Error %d enabling I2S\n", ret);
835 			return ret;
836 		}
837 
838 		ret = regmap_write_bits(i2s->regmap, STM32_I2S_CR1_REG,
839 					I2S_CR1_CSTART, I2S_CR1_CSTART);
840 		if (ret < 0) {
841 			dev_err(cpu_dai->dev, "Error %d starting I2S\n", ret);
842 			return ret;
843 		}
844 
845 		regmap_write_bits(i2s->regmap, STM32_I2S_IFCR_REG,
846 				  I2S_IFCR_MASK, I2S_IFCR_MASK);
847 
848 		spin_lock(&i2s->lock_fd);
849 		i2s->refcount++;
850 		if (playback_flg) {
851 			ier = I2S_IER_UDRIE;
852 		} else {
853 			ier = I2S_IER_OVRIE;
854 
855 			if (STM32_I2S_IS_MASTER(i2s) && i2s->refcount == 1)
856 				/* dummy write to gate bus clocks */
857 				regmap_write(i2s->regmap,
858 					     STM32_I2S_TXDR_REG, 0);
859 		}
860 		spin_unlock(&i2s->lock_fd);
861 
862 		if (STM32_I2S_IS_SLAVE(i2s))
863 			ier |= I2S_IER_TIFREIE;
864 
865 		regmap_update_bits(i2s->regmap, STM32_I2S_IER_REG, ier, ier);
866 		break;
867 	case SNDRV_PCM_TRIGGER_STOP:
868 	case SNDRV_PCM_TRIGGER_SUSPEND:
869 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
870 		dev_dbg(cpu_dai->dev, "stop I2S %s\n",
871 			playback_flg ? "playback" : "capture");
872 
873 		if (playback_flg)
874 			regmap_update_bits(i2s->regmap, STM32_I2S_IER_REG,
875 					   I2S_IER_UDRIE,
876 					   (unsigned int)~I2S_IER_UDRIE);
877 		else
878 			regmap_update_bits(i2s->regmap, STM32_I2S_IER_REG,
879 					   I2S_IER_OVRIE,
880 					   (unsigned int)~I2S_IER_OVRIE);
881 
882 		spin_lock(&i2s->lock_fd);
883 		i2s->refcount--;
884 		if (i2s->refcount) {
885 			spin_unlock(&i2s->lock_fd);
886 			break;
887 		}
888 
889 		ret = regmap_update_bits(i2s->regmap, STM32_I2S_CR1_REG,
890 					 I2S_CR1_SPE, 0);
891 		if (ret < 0) {
892 			dev_err(cpu_dai->dev, "Error %d disabling I2S\n", ret);
893 			spin_unlock(&i2s->lock_fd);
894 			return ret;
895 		}
896 		spin_unlock(&i2s->lock_fd);
897 
898 		cfg1_mask = I2S_CFG1_RXDMAEN | I2S_CFG1_TXDMAEN;
899 		regmap_update_bits(i2s->regmap, STM32_I2S_CFG1_REG,
900 				   cfg1_mask, 0);
901 		break;
902 	default:
903 		return -EINVAL;
904 	}
905 
906 	return 0;
907 }
908 
909 static void stm32_i2s_shutdown(struct snd_pcm_substream *substream,
910 			       struct snd_soc_dai *cpu_dai)
911 {
912 	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);
913 	unsigned long flags;
914 
915 	clk_disable_unprepare(i2s->i2sclk);
916 
917 	spin_lock_irqsave(&i2s->irq_lock, flags);
918 	i2s->substream = NULL;
919 	spin_unlock_irqrestore(&i2s->irq_lock, flags);
920 }
921 
922 static int stm32_i2s_dai_probe(struct snd_soc_dai *cpu_dai)
923 {
924 	struct stm32_i2s_data *i2s = dev_get_drvdata(cpu_dai->dev);
925 	struct snd_dmaengine_dai_dma_data *dma_data_tx = &i2s->dma_data_tx;
926 	struct snd_dmaengine_dai_dma_data *dma_data_rx = &i2s->dma_data_rx;
927 
928 	/* Buswidth will be set by framework */
929 	dma_data_tx->addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
930 	dma_data_tx->addr = (dma_addr_t)(i2s->phys_addr) + STM32_I2S_TXDR_REG;
931 	dma_data_tx->maxburst = 1;
932 	dma_data_rx->addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
933 	dma_data_rx->addr = (dma_addr_t)(i2s->phys_addr) + STM32_I2S_RXDR_REG;
934 	dma_data_rx->maxburst = 1;
935 
936 	snd_soc_dai_init_dma_data(cpu_dai, dma_data_tx, dma_data_rx);
937 
938 	return 0;
939 }
940 
941 static const struct regmap_config stm32_h7_i2s_regmap_conf = {
942 	.reg_bits = 32,
943 	.reg_stride = 4,
944 	.val_bits = 32,
945 	.max_register = STM32_I2S_SIDR_REG,
946 	.readable_reg = stm32_i2s_readable_reg,
947 	.volatile_reg = stm32_i2s_volatile_reg,
948 	.writeable_reg = stm32_i2s_writeable_reg,
949 	.num_reg_defaults_raw = STM32_I2S_SIDR_REG / sizeof(u32) + 1,
950 	.fast_io = true,
951 	.cache_type = REGCACHE_FLAT,
952 };
953 
954 static const struct snd_soc_dai_ops stm32_i2s_pcm_dai_ops = {
955 	.set_sysclk	= stm32_i2s_set_sysclk,
956 	.set_fmt	= stm32_i2s_set_dai_fmt,
957 	.startup	= stm32_i2s_startup,
958 	.hw_params	= stm32_i2s_hw_params,
959 	.trigger	= stm32_i2s_trigger,
960 	.shutdown	= stm32_i2s_shutdown,
961 };
962 
963 static const struct snd_pcm_hardware stm32_i2s_pcm_hw = {
964 	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP,
965 	.buffer_bytes_max = 8 * PAGE_SIZE,
966 	.period_bytes_min = 1024,
967 	.period_bytes_max = 4 * PAGE_SIZE,
968 	.periods_min = 2,
969 	.periods_max = 8,
970 };
971 
972 static const struct snd_dmaengine_pcm_config stm32_i2s_pcm_config = {
973 	.pcm_hardware	= &stm32_i2s_pcm_hw,
974 	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
975 	.prealloc_buffer_size = PAGE_SIZE * 8,
976 };
977 
978 static const struct snd_soc_component_driver stm32_i2s_component = {
979 	.name = "stm32-i2s",
980 };
981 
982 static void stm32_i2s_dai_init(struct snd_soc_pcm_stream *stream,
983 			       char *stream_name)
984 {
985 	stream->stream_name = stream_name;
986 	stream->channels_min = 1;
987 	stream->channels_max = 2;
988 	stream->rates = SNDRV_PCM_RATE_8000_192000;
989 	stream->formats = SNDRV_PCM_FMTBIT_S16_LE |
990 				   SNDRV_PCM_FMTBIT_S32_LE;
991 }
992 
993 static int stm32_i2s_dais_init(struct platform_device *pdev,
994 			       struct stm32_i2s_data *i2s)
995 {
996 	struct snd_soc_dai_driver *dai_ptr;
997 
998 	dai_ptr = devm_kzalloc(&pdev->dev, sizeof(struct snd_soc_dai_driver),
999 			       GFP_KERNEL);
1000 	if (!dai_ptr)
1001 		return -ENOMEM;
1002 
1003 	dai_ptr->probe = stm32_i2s_dai_probe;
1004 	dai_ptr->ops = &stm32_i2s_pcm_dai_ops;
1005 	dai_ptr->id = 1;
1006 	stm32_i2s_dai_init(&dai_ptr->playback, "playback");
1007 	stm32_i2s_dai_init(&dai_ptr->capture, "capture");
1008 	i2s->dai_drv = dai_ptr;
1009 
1010 	return 0;
1011 }
1012 
1013 static const struct of_device_id stm32_i2s_ids[] = {
1014 	{
1015 		.compatible = "st,stm32h7-i2s",
1016 		.data = &stm32_h7_i2s_regmap_conf
1017 	},
1018 	{},
1019 };
1020 
1021 static int stm32_i2s_parse_dt(struct platform_device *pdev,
1022 			      struct stm32_i2s_data *i2s)
1023 {
1024 	struct device_node *np = pdev->dev.of_node;
1025 	const struct of_device_id *of_id;
1026 	struct reset_control *rst;
1027 	struct resource *res;
1028 	int irq, ret;
1029 
1030 	if (!np)
1031 		return -ENODEV;
1032 
1033 	of_id = of_match_device(stm32_i2s_ids, &pdev->dev);
1034 	if (of_id)
1035 		i2s->regmap_conf = (const struct regmap_config *)of_id->data;
1036 	else
1037 		return -EINVAL;
1038 
1039 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1040 	i2s->base = devm_ioremap_resource(&pdev->dev, res);
1041 	if (IS_ERR(i2s->base))
1042 		return PTR_ERR(i2s->base);
1043 
1044 	i2s->phys_addr = res->start;
1045 
1046 	/* Get clocks */
1047 	i2s->pclk = devm_clk_get(&pdev->dev, "pclk");
1048 	if (IS_ERR(i2s->pclk)) {
1049 		if (PTR_ERR(i2s->pclk) != -EPROBE_DEFER)
1050 			dev_err(&pdev->dev, "Could not get pclk: %ld\n",
1051 				PTR_ERR(i2s->pclk));
1052 		return PTR_ERR(i2s->pclk);
1053 	}
1054 
1055 	i2s->i2sclk = devm_clk_get(&pdev->dev, "i2sclk");
1056 	if (IS_ERR(i2s->i2sclk)) {
1057 		if (PTR_ERR(i2s->i2sclk) != -EPROBE_DEFER)
1058 			dev_err(&pdev->dev, "Could not get i2sclk: %ld\n",
1059 				PTR_ERR(i2s->i2sclk));
1060 		return PTR_ERR(i2s->i2sclk);
1061 	}
1062 
1063 	i2s->x8kclk = devm_clk_get(&pdev->dev, "x8k");
1064 	if (IS_ERR(i2s->x8kclk)) {
1065 		if (PTR_ERR(i2s->x8kclk) != -EPROBE_DEFER)
1066 			dev_err(&pdev->dev, "Could not get x8k parent clock: %ld\n",
1067 				PTR_ERR(i2s->x8kclk));
1068 		return PTR_ERR(i2s->x8kclk);
1069 	}
1070 
1071 	i2s->x11kclk = devm_clk_get(&pdev->dev, "x11k");
1072 	if (IS_ERR(i2s->x11kclk)) {
1073 		if (PTR_ERR(i2s->x11kclk) != -EPROBE_DEFER)
1074 			dev_err(&pdev->dev, "Could not get x11k parent clock: %ld\n",
1075 				PTR_ERR(i2s->x11kclk));
1076 		return PTR_ERR(i2s->x11kclk);
1077 	}
1078 
1079 	/* Register mclk provider if requested */
1080 	if (of_find_property(np, "#clock-cells", NULL)) {
1081 		ret = stm32_i2s_add_mclk_provider(i2s);
1082 		if (ret < 0)
1083 			return ret;
1084 	}
1085 
1086 	/* Get irqs */
1087 	irq = platform_get_irq(pdev, 0);
1088 	if (irq < 0)
1089 		return irq;
1090 
1091 	ret = devm_request_irq(&pdev->dev, irq, stm32_i2s_isr, IRQF_ONESHOT,
1092 			       dev_name(&pdev->dev), i2s);
1093 	if (ret) {
1094 		dev_err(&pdev->dev, "irq request returned %d\n", ret);
1095 		return ret;
1096 	}
1097 
1098 	/* Reset */
1099 	rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
1100 	if (IS_ERR(rst)) {
1101 		if (PTR_ERR(rst) != -EPROBE_DEFER)
1102 			dev_err(&pdev->dev, "Reset controller error %ld\n",
1103 				PTR_ERR(rst));
1104 		return PTR_ERR(rst);
1105 	}
1106 	reset_control_assert(rst);
1107 	udelay(2);
1108 	reset_control_deassert(rst);
1109 
1110 	return 0;
1111 }
1112 
1113 static int stm32_i2s_remove(struct platform_device *pdev)
1114 {
1115 	snd_dmaengine_pcm_unregister(&pdev->dev);
1116 	snd_soc_unregister_component(&pdev->dev);
1117 
1118 	return 0;
1119 }
1120 
1121 static int stm32_i2s_probe(struct platform_device *pdev)
1122 {
1123 	struct stm32_i2s_data *i2s;
1124 	u32 val;
1125 	int ret;
1126 
1127 	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
1128 	if (!i2s)
1129 		return -ENOMEM;
1130 
1131 	i2s->pdev = pdev;
1132 	i2s->ms_flg = I2S_MS_NOT_SET;
1133 	spin_lock_init(&i2s->lock_fd);
1134 	spin_lock_init(&i2s->irq_lock);
1135 	platform_set_drvdata(pdev, i2s);
1136 
1137 	ret = stm32_i2s_parse_dt(pdev, i2s);
1138 	if (ret)
1139 		return ret;
1140 
1141 	ret = stm32_i2s_dais_init(pdev, i2s);
1142 	if (ret)
1143 		return ret;
1144 
1145 	i2s->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "pclk",
1146 						i2s->base, i2s->regmap_conf);
1147 	if (IS_ERR(i2s->regmap)) {
1148 		if (PTR_ERR(i2s->regmap) != -EPROBE_DEFER)
1149 			dev_err(&pdev->dev, "Regmap init error %ld\n",
1150 				PTR_ERR(i2s->regmap));
1151 		return PTR_ERR(i2s->regmap);
1152 	}
1153 
1154 	ret = snd_dmaengine_pcm_register(&pdev->dev, &stm32_i2s_pcm_config, 0);
1155 	if (ret) {
1156 		if (ret != -EPROBE_DEFER)
1157 			dev_err(&pdev->dev, "PCM DMA register error %d\n", ret);
1158 		return ret;
1159 	}
1160 
1161 	ret = snd_soc_register_component(&pdev->dev, &stm32_i2s_component,
1162 					 i2s->dai_drv, 1);
1163 	if (ret) {
1164 		snd_dmaengine_pcm_unregister(&pdev->dev);
1165 		return ret;
1166 	}
1167 
1168 	/* Set SPI/I2S in i2s mode */
1169 	ret = regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG,
1170 				 I2S_CGFR_I2SMOD, I2S_CGFR_I2SMOD);
1171 	if (ret)
1172 		goto error;
1173 
1174 	ret = regmap_read(i2s->regmap, STM32_I2S_IPIDR_REG, &val);
1175 	if (ret)
1176 		goto error;
1177 
1178 	if (val == I2S_IPIDR_NUMBER) {
1179 		ret = regmap_read(i2s->regmap, STM32_I2S_HWCFGR_REG, &val);
1180 		if (ret)
1181 			goto error;
1182 
1183 		if (!FIELD_GET(I2S_HWCFGR_I2S_SUPPORT_MASK, val)) {
1184 			dev_err(&pdev->dev,
1185 				"Device does not support i2s mode\n");
1186 			ret = -EPERM;
1187 			goto error;
1188 		}
1189 
1190 		ret = regmap_read(i2s->regmap, STM32_I2S_VERR_REG, &val);
1191 		if (ret)
1192 			goto error;
1193 
1194 		dev_dbg(&pdev->dev, "I2S version: %lu.%lu registered\n",
1195 			FIELD_GET(I2S_VERR_MAJ_MASK, val),
1196 			FIELD_GET(I2S_VERR_MIN_MASK, val));
1197 	}
1198 
1199 	return ret;
1200 
1201 error:
1202 	stm32_i2s_remove(pdev);
1203 
1204 	return ret;
1205 }
1206 
1207 MODULE_DEVICE_TABLE(of, stm32_i2s_ids);
1208 
1209 #ifdef CONFIG_PM_SLEEP
1210 static int stm32_i2s_suspend(struct device *dev)
1211 {
1212 	struct stm32_i2s_data *i2s = dev_get_drvdata(dev);
1213 
1214 	regcache_cache_only(i2s->regmap, true);
1215 	regcache_mark_dirty(i2s->regmap);
1216 
1217 	return 0;
1218 }
1219 
1220 static int stm32_i2s_resume(struct device *dev)
1221 {
1222 	struct stm32_i2s_data *i2s = dev_get_drvdata(dev);
1223 
1224 	regcache_cache_only(i2s->regmap, false);
1225 	return regcache_sync(i2s->regmap);
1226 }
1227 #endif /* CONFIG_PM_SLEEP */
1228 
1229 static const struct dev_pm_ops stm32_i2s_pm_ops = {
1230 	SET_SYSTEM_SLEEP_PM_OPS(stm32_i2s_suspend, stm32_i2s_resume)
1231 };
1232 
1233 static struct platform_driver stm32_i2s_driver = {
1234 	.driver = {
1235 		.name = "st,stm32-i2s",
1236 		.of_match_table = stm32_i2s_ids,
1237 		.pm = &stm32_i2s_pm_ops,
1238 	},
1239 	.probe = stm32_i2s_probe,
1240 	.remove = stm32_i2s_remove,
1241 };
1242 
1243 module_platform_driver(stm32_i2s_driver);
1244 
1245 MODULE_DESCRIPTION("STM32 Soc i2s Interface");
1246 MODULE_AUTHOR("Olivier Moysan, <olivier.moysan@st.com>");
1247 MODULE_ALIAS("platform:stm32-i2s");
1248 MODULE_LICENSE("GPL v2");
1249